A light emitting diode (referred to as “LED”) device as a kind of a semiconductor element is a lighting apparatus attracting attention as one of the so-called “energy-saving” home appliances and is used as a backlight of a liquid crystal display as well as an ordinary lighting apparatus because the electric power consumption is low and generated heat is small in comparison with an incandescent lamp for example. Although the generated heat is far smaller than that of an incandescent lamp, large electric current flows in an LED element of a high output (high intensity) type and hence heat generation and temperature rise of non-negligible levels are caused in some cases.
In view of the situation, the present applicants have already proposed a package for an LED device that improves heat dissipation and has a small thickness (refer to Patent Literature 1). The package for an LED device is a package for an LED device that: has an LED retention plane including a region for retaining an LED element and a frame member to surround the circumference of the LED retention plane; and seals an element retention space formed with the LED retention plane and the frame member with an optically transparent resin. On the LED retention plane, a cup-shaped member to retain an LED element, a lead part, and an insulative partition part to partition the cup-shaped member and the lead part from each other appear.
In such a package for an LED device in particular, a good heat dissipation effect can be obtained by making the bottom face of a bottom plate part in a cup-shaped member appear on a plane identical to the bottom face of an insulative partition part on the bottom face side of the package for the LED device and thus making electrically conductive parts of external radiation member and heat sink for cooling and a printed-circuit board stick tightly to the bottom face of the LED device in order to improve heat dissipation.
Further, in other semiconductor elements such as image sensors including a CMOS and a CCD, heat is generated during operation though the quantity is small and noises caused by the heat increase in some cases. Consequently, a heat dissipation mechanism is important also in a package on which an image sensor is mounted in some cases.